TestFlight builds automatically expire and External Testing fails with BETA_CONTRACT_MISSING – third recurrence

This one isn't on your side. There's a long-running thread on exactly this error going since February — https://developer.apple.com/forums/thread/814565 — around 30 devs in it, and every single one had all agreements showing Active, banking fine, nothing pending. Same as you. What's actually breaking is the internal TestFlight beta contract getting detached from the account on Apple's backend, which is why checking the Agreements page fixes nothing. It can't be repaired through the API either. The only thing that's worked for people: a case with Developer Account Support (developer.apple.com/contact) asking them, in those words, to re-provision / re-attach the TestFlight beta contract on the backend. A DTS engineer in that thread confirmed that's how they fix it, and said to upload a fresh build about 48 hours after — already-expired builds don't come back, which matches what you're seeing. Since this is your third round: if you still have the old case number, reopen that same case and tell them it's recurring. That tends to get it escalated instead of starting over with a new agent. And link them to that thread so they can see it's systemic, not your account.